Simulation assisted design for microneedle manufacturing: Computational modeling of two-photon templated electrodeposition

Fully metallic micrometer-scale 3D architectures can be fabricated via a hybrid additive methodology combining multi-photon lithography with electrochemical deposition of metals. The methodology - referred to as twophoton templated electrodeposition (2PTE) - has significant design freedom that enables the creation of complicated, traditionally difficult-to-make, high aspect ratio metallic structures such as microneedles. These complicated geometries, combined with their fully metallic nature, can enable precision surgical applications such as inner ear drug delivery or fluid sampling. However, the process involves electrochemical deposition of metals into complicated 3D lithography patterns thicker than 500 mu m. This causes potential and chemical gradients to develop within the 3D template, creating limitations to what can be designed. These limitations can be explored, understood, and overcome via numerical modeling. Herein we introduce a numerical model as a design tool that can predict growth for manufacturing complicated 3D metallic geometries. The model is successful in predicting the geometric result of 2PTE, and enables extraction of insights about geometric constraints through exploration of its mechanics.

Automated summary

The hybrid additive methodology of twophoton templated electrodeposition (2PTE) allows for the fabrication of fully metallic micrometer-scale 3D architectures with complex geometries, such as microneedles, for precision surgical applications. However, challenges arise from electrochemical deposition of metals into thick 3D lithography patterns, leading to potential and chemical gradients that affect design limitations. Numerical modeling serves as a design tool to predict growth and explore geometric constraints of manufacturing complicated 3D metallic structures through the 2PTE method.